Search results for "Parametric"

Distribution Dynamics and Nonlinear Growth

2003

Nanopatterned ferroelectric crystals for parametric generation

2006

We report on recent results by surface periodic poling on lithium niobate and lithium tantalate. Such approach allows periodic inversion of the second order susceptibility with nanoscale features using insulating masks. We achieved a world-best 200 nm feature size, as well as good compatibility with alpha-phase proton exchanged channel waveguides in lithium niobate. Preliminary results of surface periodic poling in lithium tantalate also show similar characteristics. Surface poling is best suited for integrated optics devices in technologically-demanding configurations such as backward second harmonic generation and counter propagating optical parametric amplification

PARAMETRIC SELF-TRAPPING OF OPTICAL BEAMS VIA RANDOM QUASI PHASE MATCHING IN LITHIUM TANTALATE WAVEGUIDE

2011

We report on experimental evidence of parametric spatial solitons in a lithium tantalate waveguide with randomized periodic ferroelectric poling. Two-color self-focusing via quadratic cascading overcomes the diffractive nature of both fundamental and frequency-doubled beams.

Modelling and Simulation of the Longterm Behaviour of Arterial Pressure Regulation with the Aid of a Block — Diagrammed Interactive Simulation System

1983

The possibility of developing a managable closed nonlinear mathematical model of the renovascular system for longterm blood pressure regulation is outlined. The developed model is a parametric one. Its structure contains explicitely the biological parameters.

Non-parametric spectrum cartography using adaptive radial basis functions

2017

This paper presents a framework for spectrum cartography based on the use of adaptive Gaussian radial basis functions (RBF) centered around a specific number of centroid locations, which are determined, jointly with the other RBF parameters, by the available measurement values at given sensor locations in a specific geographical area. The spectrum map is constructed non-parametrically as no prior knowledge about the transmitters is assumed. The received signal power at each location (over a given bandwidth and time period) is estimated as a weighted contribution from different RBF, in such a way that the both RBF parameters and the weights are jointly optimized using an alternating minimiza…

How do normalization schemes affect net spillovers? A replication of the Diebold and Yilmaz (2012) study

2019

Abstract This paper replicates the Diebold and Yilmaz (2012) study on the connectedness of the commodity market and three other financial markets: the stock market, the bond market, and the FX market, based on the Generalized Forecast Error Variance Decomposition, GEFVD. We show that the net spillover indices (of directional connectedness), used to assess the net contribution of one market to overall risk in the system, are sensitive to the normalization scheme applied to the GEFVD. We show that, considering data generating processes characterized by different degrees of persistence and covariance, a scalar-based normalization of the Generalized Forecast Error Variance Decomposition is pref…

Visual aftereffects and sensory nonlinearities from a single statistical framework

2015

When adapted to a particular scenery our senses may fool us: colors are misinterpreted, certain spatial patterns seem to fade out, and static objects appear to move in reverse. A mere empirical description of the mechanisms tuned to color, texture, and motion may tell us where these visual illusions come from. However, such empirical models of gain control do not explain why these mechanisms work in this apparently dysfunctional manner. Current normative explanations of aftereffects based on scene statistics derive gain changes by (1) invoking decorrelation and linear manifold matching/equalization, or (2) using nonlinear divisive normalization obtained from parametric scene models. These p…

Zenith angle distributions at Super-Kamiokande and SNO and the solution of the solar neutrino problem

2000

We have performed a detailed study of the zenith angle dependence of the regeneration factor and distributions of events at SNO and SK for different solutions of the solar neutrino problem. In particular, we discuss oscillatory behaviour and the synchronization effect in the distribution for the LMA solution, the parametric peak for the LOW solution, etc.. Physical interpretation of the effects is given. We suggest a new binning of events which emphasizes distinctive features of zenith angle distributions for the different solutions. We also find the correlations between the integrated day-night asymmetry and the rates of events in different zenith angle bins. Study of these correlations st…

A method for the calculation of the heat transfer coefficient in potato drying

1993

A method for the determination of the heat transfer coefficient was proposed for the first falling drying period of potato cubes. During this period, heat and mass transfer were considered as coupled phenomena. Temperature calculation inside the sample was performed using the macroscopic heat transfer balance. The heat transfer coefficient was computed by means of parametric identification, using the Gauss–Newton method. The figure obtained for the heat transfer coefficient shows good agreement with other sources.

A correction method for the analysis of continuous linear one-dimensional systems under moving loads

2008

A new correction procedure for dynamic analysis of linear, proportionally damped, continuous systems under traveling concentrated loads is proposed; both cases of non-parametric (moving forces) and parametric (moving mass) loads are considered. Improvement in the evaluation of the dynamic response is obtained by separating the contribution of the low-frequency (LF) modes from that of the high-frequency (HF) modes. The former is calculated, as usual, by classical modal analysis, while the latter is taken into account using a new series expansion of the corresponding particular solution. The advantage of the suggested method is immediately shown in the calculation of the stress distribution s…